Project description:Sonography is an important clinical tool in diagnosing appendicitis in children as it can obviate both exposure to potentially harmful ionising radiation from computed tomography scans and the need for unnecessary appendicectomies. This review examines the diagnostic accuracy of ultrasound in the identification of acute appendicitis, with a particular focus on the the utility of secondary sonographic signs as an adjunct or corollary to traditionally examined criteria. These secondary signs can be important in cases where the appendix cannot be identified with ultrasound and a more meaningful finding may be made by incorporating the presence or absence of secondary sonographic signs. There is evidence that integrating these secondary signs into the final ultrasound diagnosis can improve the utility of ultrasound in cases where appendicitis is expected, though there remains some conjecture about whether they play a more important role in negative or positive prediction in the absence of an identifiable appendix.
Project description:BackgroundPulmonary ultrasound plays a key role in the diagnosis of pneumothorax in emergency and intensive-care medicine. The lung point sign has been generally considered a pathognomonic diagnostic sign. Recently, several other situations have been published that can mimic the lung point, as well as a few different variants of the true lung point sign.Materials and methodsBased on years of monitoring the literature and collecting our database of ultrasound findings, we prepared a review of ultrasound findings mimicking the lung point sign and ultrasound variants of the true lung point sign.ResultsWe present four imitations of the lung point sign (physiological lung point sign, pseudo-lung point sign, bleb point sign, and pleurofascial point sign) and two variants of the true lung point sign (double lung point sign and hydro point sign) documented by images and video records.ConclusionsKnowledge of ultrasound imitations and variants of the lung point sign may increase the reliability of pneumothorax diagnosis and may reduce the risk of performing unindicated interventions.
Project description:We report a case of fulminant COVID-19-related myocarditis requiring venoarterial extracorporeal membrane oxygenation where the use of an ultrasound-enhancing agent demonstrated a previously undescribed echocardiographic finding, the "lightbulb" sign. This sign potentially represents a new area for the use of an ultrasound enhancing agent in the echocardiographic diagnosis of myocarditis.
Project description:BackgroundHemoptysis is the most frequently reported complication of ultrasound-guided transthoracic needle lung biopsy (US-TTLB). However, factors influencing the occurrence of hemoptysis as a result of US-TTLB remain uncertain. Therefore, the aim of this study was to evaluate the incidence of hemoptysis as a complication of US-TTLB and to identify the related risk factors.MethodsWe retrospectively analyzed all data of patients who underwent US-TTLB from February 2013 through December 2016. The incidence, severity, and treatment of hemoptysis in each case were carefully recorded. Study variables were classified into patient-related factors (age, sex, smoking history, pulse oxygen saturation, laboratory tests and emphysema), biopsy-related factors (use of contrast agent, number of punctures and operators), and lesion-related factors (lesion location, size, pathology, length of puncture path and the grade of air bronchial sign). Univariate and multivariate logistic regression analyses were performed to analyze the risk factors of hemoptysis. We investigated whether incidence of hemoptysis increased according to increased grade of air bronchial sign by Mantel-Haenszel test.ResultsA total of 209 patients were evaluated. Hemoptysis occurred in 20 of the 209 patients (9.6%). In univariate analysis, the lesion pathology (P=0.037) and grade of air bronchial sign (P<0.001) were statistically significant factors between the hemoptysis group and the non-hemoptysis group. In multivariate analysis, the presence of multi-air bronchogram in sonographic image (odds ratio =8.946; 95% confidence interval: 2.873-27.863; P<0.001) was a statistically significant predictive risk factor for hemoptysis complicating US-TTLB. There was a significant tendency for incidence of hemoptysis with the grade of air bronchial sign (P<0.001).ConclusionsWe found that the rate of hemoptysis complicating US-TTLB was 9.6% and the severity of hemoptysis was not serious. Target lesion without air bronchogram is a safety sign, minor bronchogram means relatively low-risk, while multiple bronchogram is a highly dangerous ultrasound sign of hemoptysis.
Project description:MotivationMetagenomic samples have high spatiotemporal variability. Hence, it is useful to summarize and characterize the microbial makeup of a given environment in a way that is biologically reasonable and interpretable. The UniFrac metric has been a robust and widely used metric for measuring the variability between metagenomic samples. We propose that the characterization of metagenomic environments can be improved by finding the average, a.k.a. the barycenter, among the samples with respect to the UniFrac distance. However, it is possible that such a UniFrac-average includes negative entries, making it no longer a valid representation of a metagenomic community.ResultsTo overcome this intrinsic issue, we propose a special version of the UniFrac metric, termed L2UniFrac, which inherits the phylogenetic nature of the traditional UniFrac and with respect to which one can easily compute the average, producing biologically meaningful environment-specific "representative samples." We demonstrate the usefulness of such representative samples as well as the extended usage of L2UniFrac in efficient clustering of metagenomic samples, and provide mathematical characterizations and proofs to the desired properties of L2UniFrac.Availability and implementationA prototype implementation is provided at https://github.com/KoslickiLab/L2-UniFrac.git. All figures, data, and analysis can be reproduced at https://github.com/KoslickiLab/L2-UniFrac-Paper.